A pressure measuring device is formed as, for example, a high-pressure sensor mounted on a vehicle and is used to measure a fuel pressure of an engine, a brake hydraulic pressure, various kinds of gas pressures, and the like.
For example, PTLs 1 and 2 propose conventional pressure measuring devices.
PTL 1 discloses “a pressure detector formed by bonding plate glass a diaphragm surface of pressure-receiving metal diaphragm visa low-melting glass layer, placing a strain gauge semiconductor chip on the plate glass, and performing anodic bonding on the plate glass and the strain gauge semiconductor chip”.
PTL 2 discloses “a pressure sensor in which a sensor element is bonded to a diaphragm by a bonding member having a first bonding surface bonded to the sensor element and a second bonding surface bonded to the diaphragm formed in a metal stem, wherein the bonding member is formed so that a coefficient of thermal expansion of the first bonding surface is closer to a coefficient of thermal expansion of the sensor element than to a coefficient of thermal expansion of the metal stem, a coefficient of thermal expansion of the second bonding surface is closer to the coefficient of thermal expansion of the metal stem than to the coefficient of thermal expansion of the sensor element, and the coefficient of thermal expansion is continuously changed from the first bonding surface the second bonding surface”.